The thesis examines the attitudes which lay behind the different laws relating to marriage and sexual offences enacted between 1560 and 1707 by the Scottish Parliament, the Privy Council and the General Assemblies of the Church of Scotland. The Canon Law as it was taught in Scotland in Scotland in the 1530's is considered as it is necessary to identify both the changes between and the continuity of pre- and post-Reformation law. The particular topics included under 'marriage' are the regulations on the celebration of marriage, the penalties for irregular or clandestine marriages, the legal proofs for the existence of a marriage, and the introduction of divorce 'a vinculo' on the grounds of adultery and desertion. The sexual offences are incest, adultery, and fornication (including ante-nuptial fornication). The legislation passed by the central authorities represents the 'official' attitudes to sex and marriage but it does not necessarily reflect the attitudes of every section of society nor of actual behaviour. This material is therefore supplemented by examples derived from other published sources - kirk sessions, burgh councils, Court of Justiciary - local regulations and of the application of the law in particular cases. The evidence suggests that it is possible to outline a general moral code but that there were conflicting views on the definition of particular offences and the appropriate penalties. The thesis confirms the importance of undisputed paternity and the system of inheritance in discussing attitudes to sex and marriage, and shows that 'moral' legislation was as much a product of political events as other Acts of Parliament.